The correct answer is C, quote directly or paraphrase.
Explanation:
When historians write essays they have to include citations of other works so readers can follow the arguments they are making.
These citations are made in the form of direct quotesbetween quotation marks that must direct the reader to the exact source of it or in the form of paraphrase, that is when the author explains with his/her words the ideas of another author -- and this must also direct the reader to the exact source of the idea.
Citations are essential to the critical examination of the essay regarding its adequacy to the scientific method.
